High temperature processing of exposed photographic elements



United States Patent 3,536,486 HIGH TEMPERATURE PROCESSING OF EXPOSEDPHOTOGRAPHIC ELEMENTS Leo E. Beavers, Rochester, N.Y., assignor toEastman Kodak Company, Rochester, N.Y., a corporation of New Jersey NoDrawing. Filed Feb. 3, 1969, Ser. No. 796,172

Int. Cl. G03c 5/50 US. Cl. 96-22 31 Claims ABSTRACT OF THE DISCLOSUREThe present invention relates to photographic processes, and moreparticularly to photographic processes for providing multicolorreproductions.

The dyes employed in providing multicolor photographic reproductions arenot always true colors. For

example, magenta dyes often have small amounts of blue I lightabsorption and red light absorption. Similarly, yellow dyes and cyandyes absorb small amounts of light other than blue and red light,respectively. The effects of such unwanted absorptions by dyes employedin photographic multicolor processes is the production of dark anddesaturated colors or color hue errors.

Such deficiencies in dyes employed in multicolor photographic processescan be compensated, at least in part, by creating certain interimageeffects. The interimage effects to which this invention pertains arereferred to herein as undercut interimage effects. In accordance withthis invention, novel means are provided for inducing undercutinterimage effects in processes for providing multicolor photographicreproductions.

It is one object of this invention to provide a novel method forcorrecting unwanted absorptions of dye images formed in photographicmulticolor processes.

It is another object of this invention to provide a novel method forproviding undercut interimage effects in photographic multicolorprocesses which utilize at least one photographic silver haloiodideemulsion layer.

It is a further object of this invention to provide a novel method forintroducing undercut interimage effects in photographic processes forproviding multicolor images.

It is still another object of this invention to provide multicolorphotographic processes which result in increased contrast, speed,sharpness and reduced color contamination.

Still other objects of this invention will be apparent from thedisclosure herein and the appended claims.

In accordance with one embodiment of this invention, an improvement isprovided in photographic multicolor processes which includes (1)developing silver images in 3,536,486 Patented Oct. 27, 1970 an exposedphotographic element having at least two superposed hydrophilic colloidlayers containing lightsensitive silver halide, and (2) formingdifferently colored dye images in proportion to said silver images. Thisimprovement resides in introducing a diffusible 4-thiazoline- 2-thioneinto the exposed photographic element so that 4-thiazoline-2-thione ispresent during development of the silver images. When a diffusible4-thiazoline-2-thione is present during the formation of silver imagesin multicolor photographic processes of the type described above,undercut interimage effects are obtained in the completed multicolorphotographic reproduction.

'Interimage effects are Well known in photographic multicolor processes.See, for example, Hanson and Horton, Journal of the Optical Society ofAmerica, vol. 42, No. 9, pages 663-669, September 1952, and Pinney,Interimage Effects and Color Reproduction, The SPSE Reporter, November1960. The interimage effects produced by the present invention arereferred to herein and in the appended claims as undercut interimageeffects. Undercut interimage effects are characterized by repression ofa given color scale produced by a neutral exposure, and the lack of suchrepression for that color scale in a single color exposure.

A more specific, hypothetical example will further illustrate themeaning of undercut interimage effects. A photographic element isprovided containing two light-sensitive silver halide emulsion layers.One of these layers is sensitive to red radiation and is adapted to formcyan dye. The second layer is sensitive to blue radiation, and formsyellow dye. One sample of such a film is given a stepped exposure to redlight. A second sample is given a stepped exposure to red plus bluelight. The amount of red light is the same in each exposure. Undercutinterimage effects are present when the cyan dye produced from theexposure to red light only is less than the cyan dye produced from theexposure to red plus blue light. A similar analysis can be made forother dye images, such as red, green, blue, magenta and yellow.

Undercut interimage effects result in more saturated and brighter dyeimages. These interimage effects can be measured by the proceduresdescribed by Pinney or Hanson and Horton, referred to above.

As noted, the compounds employed in this invention to induce undercutinterimage effects include the diffusible 4-thiazoline-2-thiones. Thesecompounds generally are, at least in solution, in equilibrium with theircorresponding mercaptan forms. The compounds should be capable offorming a complex with silver halide, thereby rendering the compoundnon-diffusible unless the silver halide is developed to a silver image.One especially useful class of 4-thiazoline-2-thione compounds has, inthe 4-position thereof, an alkyl substituent having a carbonyl orhydroxyl group. As used herein and in the appended claims, the termcarbonyl has its usual meaning, i.e., =C=O. Typical useful alkylsubstituents containing a carbonyl group include formyl, carboxyl,alkoxy- Icarbonyl, e.g., ethoxycarbonyl, and allkoxyalkyl, e.g.,acetoxymethyl. Another highly useful class of 4-thiazoline-Z-thionescontains an alkyl substituent in the 4-position thereof, said alkylsubstituent consisting of from 4 to 5 carbon atoms, each of the carbonatoms having a hydroxyl group attached thereto. As used herein, the term4-thiaz0line-2-thione refers to the 3-hydrogen subgeneral formula:

l N X'- wherein X represents alkyl such as methyl or ethyl; an alkylsubstituent containing at least one hydroxyl group such as hydroxymethyl, [i-hydroxyethyl, gluco or arabino; or an alkyl substituenthaving at least one carbonyl-containing group such as formyl, carboxyl,ethoxy carbonyl or acetoxy methyl; and, Z is independently se ected froma value given for X, and preferably represents hydrogen. Advantageously,the 4-thiazoline-2-thione compound employed is one which can emolize toits corresponding mercaptan form. Enolization can take place at anysuitable time, such as when the 4-thiazoline- 2-thione is added to ahydrophilic colloid layer containing light sensitive silver halide.

Representative dilfusible 4-thiazoline-2-thiones which can beadvantageously employed in the practice of this invention include thefollowing:

(3) 4-carboxy-4-thiazoline-2-thione COOH TNH l l. S

(4) 4-carboxy-5-methyl-4-thiazoline-2-thione COOH I EI l r (5)4-carbethoxy-4-thiazoline-2-thione (6)4-acetoxymethyl-4-thiazoline-Z-thione 4 (7)4-(D-arabino-tetraacetoxybutyl)-4-thiazoline-2- o 11 0 020E H H0 0 o o 0Ha HC 0 o 0 CH3 orrzocoorr (8) 4- D-gluco-penta-acetoxypentyl)-4-thiazoline-2- thione l g H H I OCOCH CH3CO2CH HCOOOCH l HCOOOCH;

C HzOCOCHs (9) 4- (D-gluco-penta-hydroxypentyl) -4-thiazoline-2- thioneHC OH HOOH HJJOH l ENIJOH CHaOH (l0)4-hydroxymethyl-4-thiazoline-2-thione N H l E3011 11)4-methyl-4-thiazoline-2-thione 12)4-(D-arabino-1,2,3,4-tetrahydroxybutyl)-4- thiazoline-Z-thione As isknown, several isomers of compound 12 exist; Any of these isomers, ormixtures thereof, can be employed in accordance with this invention toproduce undercut interimage effects.

The 4-thiazoline-2-thiones employed in this invention are ditfusible inhydrophilic colloids. As used herein, the term ditfusible denotesmaterials having the property of moving effectively through the colloidlayers of the photographic elements employed. Thus, it follows that anysubstituents on the subject compounds should not, alone or in theircombined action, prevent diffusion of the compounds through the colloidlayers employed in the photosensitive element. In short, thesubstituents of such compounds should be non-ballasting. Although we donot wish to be limited to any theory as to the nature of the operationof the invention, it seems reasonable to believe that the4-thiazoline-2-thiones become attached to silver halide crystals, andare prevented from diffusing freely through the colloid layers of thephotographic element. However, when the silver halide is developed tosilver image, it seems that the 4-thiazoline-2-thione is thus releasedand is diffused imagewise in the system, and probably inhibitsdevelopment.

In order to obtain undercut interimage effects in accordance with theinvention, the diffusable 4-thiazoline-2- thiones must be present in thephotosensitive element during the development of silver image (i.e., theinitial development of silver image). The photosensitive element canalso be treated subsequent to exposure, such as "with an aqueoussolution containing the diifusable interimage producing addenda of theinvention. Such aqueous solutions can contain various photographicallyuseful reactants, such as prehardener. The compounds of the inventioncan also be added to the developer solution employed to develop silverimage in the exposed photographic element.

The effective concentration of the addenda in accordance with thisinvention can be varied over a considerable range. The concentrationemployed depends on the particular light sensitive silver halideemulsions utilized, the concentration of silver halide in the emulsionlayers, and the concentration of dye to be formed. A highly usefulconcentration range of addenda is from about 0.1 mg. to about 1.0 g.addenda per liter of solution (such as blackand-white developersolution) with about 1.0 mg. to 50 mg. addenda per liter of solutionbeing the range generally preferred.

The 4-thiazoline-2-thione undercut interimage producers can be used toadvantage with any compound which functions to develop silver image in asilver halide layer containing a latent image. Highly useful classes ofsilver image developing agents include the polyhydroxy benzenes,N-monoalkylamino phenols and mixtures of polyhydroxy benzenes andN-monoalkylamino phenols. Typical useful polyhydroxy benzenes includehydroquinone, catechol, pyrogallol, etc., and typical usefulN-substituted aminophenols include N-methylamino phenols, N-ethylaminophenols, etc., or mixtures of such developers. Prominent among suchdeveloping agents are those which provide rapid development ofphotographic images comprising hydroquinone and p-N-methylarnino phenol.The developing agents with which the undercut interimage increasingaddenda of this invention can be used include dye developers, such asthose disclosed and referred to in Weyerts et al. U.S. Pat. 3,146,102issued Aug. 25, 1964, and Rogers U.S. Pat. 2,983,606 issued May 9, 1961.The addenda of this invention can also be used in the photographic colorprocesses described in Whitmore et al., U.S. Pat. 3,227,550, issuedSept. 7, 1962; Barr et al., U.S. Pat. 3,227,551, issued Jan. 4, 1966;Whitmore U.S. Pat. 3,227,552, issued Jan. 4, 1966; Barr et al. U.S. Pat.3,227,554, issued Jan. 4, 1966; or Barr U.S. Pat. 3,243,- 294, issuedMar. 29, 1966.

Desirable undercut images are obtained in accordance with this inventionwhen the processing is conducted at conventional temperatures, such asabout 68 to 75 F., or when higher processing temperatures are employed,such as from 75 F. up to about 180 F., or higher.

The undercut interimage producing addenda of this invention can be usedin any process of providing multicolor photographic reproductions whichincludes (1) developing silver images in an exposed photographic elementhaving at least two superposed hydrophilic colloid layers containingsilver halide, and (2) forming differently colored dye images inproportion to said silver images. For example, the addenda are highlyuseful in complete photographic reversal processes wherein a multilayerphotographic element containing a plurality of differentially sensitizedphotographic silver halide emulsion layers is given a first exposure,followed by development in a photographic developer for producing ablack-and-white silver negative image, and a second exposure followed byat least one additional development in a photographic developer forproducing a colored dye image. In such systems, the dye image may beprovided in one of two classical techniques. In one, color couplers areincorporated in or contiguous to the photographic emulsions prior toexposure. Gen erally, the color forming couplers are dispersed in asuitable medium, such as one of those described in US. Pats. 2,322,027or 2,304,940. Representative useful color formers which may be used insuch processes are well known in the literature, and are described forexample, in Fierke et al., U.S. Pat. 2,801,171; Weissberger et al., U.S.Pat. 2,474,293; Glass et al., U.S. Pat. 2,521,908; and Mc- Crossen etal., U.S. Pat. 2,857,057. Such elements can be developed by one of theprocesses described and referred to in Graham et al. U.S. Pat.3,046,129, col. 23 and 24. General classes of useful color formersinclude phenolic, S-pyrazolone, and open chain ketornethylene compounds.

The second of such color reversal photographic processes ischaracterized by the introduction into the photosensitive element of dyeformer contained in the developer. In such processes, couplers of thetype referred to above can be incorporated in a color developersolution. These processes are described in the literature, such asMannes et al., U.S. Pat. 2,252,718, issued Aug. 19, 1941.

The color forming developers which can be used in accordance with thetwo processes described above have been previously described in the art.The most useful of such color forrning developers are the phenylenediamines and substituted derivatives thereof, such as those disclosed inWeissberger et al., U.S. Pat. 2,548,574, issued Apr. 10, 1951;Weissberger et al., U.S. Pat. 2,552,- 240-2 issued May 8, 1951; andWeissberger et al., U.S. Pat. 2,566,271, issued Aug. 28, 1951. Otherphenylene diamine color forming developers can be employed to advantagein the process of this invention.

This invention is also applicable to other photographic processes forforming multicolor images, such as color diffusion transfer processes ofthe type described in Rogers U.S. Pat. 2,983,606, issued May 9, 1961;Weyerts U.S. Pat. 3,146,102, issued Aug. 25, 1964; Barr et al. U.S. Pat.3,227,551, issued Jan. 4, 1966; Barr et al. U.S. Pat. 3,227,554, issuedIan. 4, 1966; Barr U.S. Pat. 3,243,- 294, issued Mar. 29, 1966; Whitmoreet al., U.S. Pat. 3,227,550, issued Jan. 4, 1966; and Whitmore U.S. Pat.3,227,552, issued Aug. 27, 1964.

The novel addenda of this invention can also be employed to advantage inphotographic processes which provide dye images by the photographicsilver dye bleach process. In such processes, which are described in theliterature, bleachable dye is incorporated in or contiguous to a givensilver halide layer, a silver image is produced after exposure, and thedye is bleached imagewise in proportion to the silver image developed toprovide contrasting dye images.

As is known, one highly useful arrangement of light sensitive silverhalide layers for the provision of multicolor photographic recordscomprises a support having coated thereon, respectively, superposedlight sensitive silver halide colloid layers which are sensitive,respectively, to red, green and blue radiation. Silver images can bedeveloped in such layers, and dyes formed imagewise in proportion to thedeveloped silver image. Advantageously, cyan, magenta and yellow dyesare formed in proportion to the red, green and blue layers respectively.Such dyes can be formed in any convenient manner, such as in the colorprocesses referred to above. Advantageously, a dye image is formedhaving a complementary relationship to the region of the spectrum towhich the silver halide emulsion is sensitized.

The addena which has been described herein can be added to emulsionscontaining various light sensitive silver halide salts, such as silverbromide, silver iodide, silver chloride, or mixed silver halides, suchas silver chlorobromide, silver bromoiodide or silver chlorobromoiodide.Best results are obtained when at least one emulsion layer containssilver haloiodide, such as silver chloroiodide, or preferably silverbromoiodide (or silver bromochloroiodide). Advantageously, the silverhaloiodide contains from 1 to 10 mole percent, and preferably 4 to 8mole percent, iodide. The emulsions can contain various chemicalsensitizers, optical sensitizers, stabilizers, speed increasingcompounds, plasticizers, hardeners and coating aids, such as aredescribed and referred to in Beavers US. Pat. 3,039,873, issued June 19,1962, cols. 9-12. The light sensitive silver halide salts can bedispersed in various binders, such as the colloids described andreferred to in aforementioned Beavers patent, col. 13. Any suitablesupport can be used, such as a cellulose ester, poly(ethyleneterephthalate), paper, baryta coated paper, polyolefin coated paper suchas polyethylene or polypropylene coated paper, which can be electronbombarded to promote emulsion adhesion. Emulsion layers having differentspeeds can be utilized to extend the latitude of the element.

The following examples are included for a further understanding of theinvention. In the examples, two types of photographic elements areemployed. The first element, referred to herein as Type I, is preparedby coating a transparent poly(ethylene terephthalate) film support withthe following hydrophilic colloid layers, in the order in which they aregiven starting from the support:

TYPE I Layer A-antihalatin A dispersion of gray colloidal silver ingelatin is coated over the support at a concentration of 455 milligramsper square foot gelatin and 23 milligrams per square foot gray colloidalsilver.

Layer B-interlayer A gelatin interlayer is coated over the antihalationlayer at the rate of 115 milligrams gelatin per square foot.

Layer C-cyan-producing layer A gelatin silver bromoiodide emulsioncontaining a dispersion of a mixture of cyan-forming coupler, e.g.,couplers Nos. 1 through 6 of Fierke et al. U.S. Pat. 2,801,171 (column2) in conventional coupler solvent such as tri-o-cresyl phosphate iscoated at the rate of 110 milligrams per square foot gelatin, 65milligrams per square foot silver and 50 milligrams per square foot cyancoupler mixture. Red sensitization (600-700 mg) is provided withspectral sensitizing dye.

Layer D-interlayer A gelatin layer coated at the rate of 60 milligramsgelatin per square foot.

Layer E-magenta-producing layer A silver bromoiodide gelatin emulsionspectrally sensitized to green radiation (500-600 m with a spectralsensitizing dye and containing a dispersion in tri-o-cresyl phosphate ofa pyrazolone coupler, e.g., couplers number 7 etc. of Fierke et al. US.Pat. 2,801,171 (column 2) together with a pyrazolone coupler, e.g.,coupler number 8 of US. Pat. 2,801,171 is coated at the rate of 165milligrams per square foot gelatin, 95 milligrams per square foot silverand 65 milligrams per square foot coupler mixture.

Layer Fyellow filter layer A gelatin layer containing Carey-Leacolloidal silver is coated at the rate of 90 milligrams per square footgelatin, and 10 milligrams per square foot silver.

Layer Gyellow-producing layer A gelatin silver bromoiodide emulsion(blue-sensitive) containing a yellow image-forming coupler, e.g.,coupler Nos. I to V of McCrossen et al., US. Pat. 2,875,057, issued Feb.24, 1959, dispersed in dibutyl phthalate is 8 coated at a concentrationof 115 milligrams per square foot gelatin, 70 milligrams per square footsilver and 50 milligrams per square foot color coupler.

Layer H-overcoat layer A gelatin layer is coated at the rate ofmilligrams per square foot gelatin.

In the following examples, all elements of Type I are processed in thefollowing reversal color process: first, the exposed film is developedfor 10 minutes in a Developer A having the following composition:

Sodium hexametaphosphate-2.0 g. N-methyl-p-aminophenol sulfate6.0 g.

Sodium sulfite, anhydrous50.0 g.

Hydroquinone6.0 g.

Sodium carbonate monohydrate-35 .0 g.

Potassium bromide-2.0 g.

Sodium thiocyanate1.5 g.

0.5% solution of 6-nitrobenzimidazole nitrate12.0 cc. 0.1 solution ofpotassium iodide-40.0 cc.

Water to make 1 liter.

The element is then thoroughly washed for one minute with water andtreated for 3 minutes in a hardening bath having the followingcomposition:

Postassium chrome alum crystals30.0 g. Water to make 1 liter.

The element is then thoroughly washed for 3 minutes with water andtreated for 30 seconds in a solution having the following composition:

Sodium borohydride0.25 g. Sodium hydroxide-40 g. Water to make 1 liter.

The element is then treated for 15 minutes in a color developer havingthe following composition:

Sodium thiosulfate--150.0 g. Sodium bisulfite20.0 g. Water to make 1liter.

The element is then treated for 8 minutes in a bleach bath having thefollowing composition:

Potassium dichromate5.0 g. Potassium ferricyanide70.0 g. Potassiumbromide-20.0 g. Water to make 1 liter.

The element is again washed for one minute and treated for 4 minuteswith the clearing and fixing bath identified above. The element iswashed for 8 minutes and treated for one minute in a stabilizing bathhaving the following composition:

Formaldehyde (37% by weight)7.0 cc. Dispersing agent 0.5 g. Water tomake 1 liter.

1 Such as Triton X100, i.e., on alkylaryl p'olyether alcollOl(octylphenoxy polyethoxy ethanol).

The above processing is referred to as Processing Procedure I in theexamples. The temperature of each bath and solution in this processingis 75 F.

The second type of photographic element employed in the followingexamples, Type II, is the same as Type I except that Type II elements donot contain any incorporated color-former. These Type II elements areprocessed by a procedure of the type described in Mannes et al. US. Pat.2,252,718, issued Aug. 19, 1941, page 2, col. 2, line 48 through page 3,col. 1, line 5. This processing is referred to in the examples asProcessing Procedure II and is defined more fully below:

PROCESSING PROCEDURE II Step: Time Prehardener 2 min. Water wash 30 sec.MQ Developer 3 min. 40 sec. Water wash l min. Red light exposed throughsupport. Cyan Developer 4 min. 30 sec. Water wash 2 min. Blue lightexposed through emulsion. Yellow developer 4 min. Water wash 2 min.Borohydride bath 1 min. Water Wash 30 sec. Magenta developer 5 min. 30sec. Water wash 4 min. Ferricyanide bleach 2 min. Hypo Fix bath 2 min.Water wash 4 min. Dry.

The solutions have the compositions given below:

Prehardener:

Sodium hexametaphosphate0.5 g. Sulfuric Acid1.7 m1. Sodium tetraborate5H O .0 g. Sodium bromide2.0 g. Sodium sulfate200.0 g. Formalin (37.5%)20.0 ml. Sodium bisulfitel.0 g. Water to make-1 liter. developer:Sodium hexametaphosphate0.6 g. Sodium sulfite79.0 g.Monomethyl-p-aminophenyl sulfate5.0 g. Sodium hydroxide1.0 g.Hydroquinoneg. Sodium carbonate-35.0 g. Potassium iodide (0.1%)-12.5 ml.Sodium bromide3.0 g. Sodium thiocyanate1.7 g. Hydroquinonemonosulfate4.0 g. Water to make 1 liter. Cyan developer:

Sodium hexametaphosphate--0.6 g. Sodium bromide-2.5 g.S-nitrobenzimidazole nitrate (1% in .1% NaOH) 3.0 ml. Potassium iodide(0.1% )l 1.0 ml. Sodium sulfite10.0 g. Sodium sulfate-60.0 g. Sodiumhydroxide3.8 g. Sodium thiocyanate1.0 g. Hydroxylamine sulfate0.65 g. 4amino N ethyl-N-B-hydroxyethyl-3-methyl aniline sulfate2.05 g. l-hydroxyN (Z-acetamidophenethyl)-2-naphthamide-1.65 g. Hexylene glycol-50 ml.Polyoxyethylene (m. wt. 1540)-1.0 g. N-benzyl-p-aminophenyl.45 g.Methanol2.0 ml. p-Aminophenol.16 g. Water to make 1 liter.

10 Yellow developer:

Sodium hexametaphosphate-0.6 g. Sodium sulfite10.0 g. Sodium bromide.55g. Polyoxyethylene (m. wt. 4000)1.0 g. Potassium iodide (0.1% )26.0 ml.N,N-diethyl-p-phenylenediamine HCl-3.0 g. 5-nitrobenzimidazole-10.0 ml.Sodium hydroxide2.l g. Sodium sulfate-64.0 g. Hexylene glycol10.0 ml.ot-Benzoyl-2-methoxyacetanilide1.5 g. Diethylhydroxylamine-1.38 ml.1-phenyl-3-pyrazolidone-0.5 g. Water to make 1 liter. Borohydride bath:

Sodium hexametaphosphate0.6 g. Sodium hydroxide- 2.16 g. Potassiumborohydride-0.l0 g. Water to make 1 liter. Magenta developer:

Sodium hexametaphosphate4.0 g. Sulfuric acid-21 ml. Sodium phosphate12H-40.0 g. Sodium sulfite5.0 g. Sodium thiocyanatel.0 g. Potassium iodide(0.1% )7.5 ml. Sodium bromide-0.5 g. Sodium sulfate-60.0 g. 4amino-N-ethyl-N-(p-methane-sulfonamidoethyl)- m-toluidine sesquisulfatemonohydrate-2.9 g. Citrazinic acid-0.72 g. Ethylenediamine3.0 ml.Polyoxyethylene (in. wt. 4000)-10.0 ml. Hexylene glycol-10.0 ml.1-(2,4,6-trichlorophenyl) 3 (4-nitroanilino)-5- pyrazolone1.67 g. Sodiumhydroxide0.32 g. Water to make 1 liter. Ferricyanide bleach bath:

Sodium bromide-35.0 g. Potassium ferricyanide-10H O200.0 g. Sodiumhydroxide0.1 g. Sodium tetraborate-5H O-1.0 g. Water to make 1 liter.Hypo fix bath:

Sodium thiosulfate220.0 g. Sodium sulfite-10.0 g. Sodium hydroxide.15 g.Water to make 1 liter.

EXAMPLE 1 Several photographic elements of Type 1 are prepared. Separateareas of each of these elements are given a single color sensitometricexposure to red, green and blue light, respectively. Unexposed portionsof each photographic element are then given an equivalent neutralsensitometric exposure consisting of red plus green plus blue light. Thered, green and blue of the neutral exposure is the same as the singlecolor red, green and blue exposures, respectively. One exposed elementis processed by Processing Procedure I; the other exposed elements areprocessed in the same way except that a 4-thiazoline-2-thione is addedto Developer A of Processing Procedure I. Density curves are plotted foreach of the cyan, magenta and yellow dye densities formed from the red,green and blue light exposures, respectively, and for the respectivecyan, magenta and yellow dye densities formed by the neutral exposure.The resulting single color density curves are compared for speed (A logE) to the same color density curves of the neutral exposure at 0.6density. The improvement in undercut interimage effects is shown inTable I, and is indicated by the increased A log E speed at 0.6 densityof a given color scale compared with the corresponding color scaleresulting from the neutral exposure.

TABLE I Concentration of A log E at 0.6 density addenda in Addendadeveloper A Cyan Magenta Yellow Control 13 03 11 Compound 12 4.2 X 10*moles 29 06 18 per liter.

Several photographic elements of Type II are prepared and exposed asdescribed in Example 1. The exposed photographic elements are processedby Processing Procedure II above, except that in processing the test elements, 100 mguof compound 12 is added to the prehardener. The A log E at0.6 density is determined, with the results shown in Table II.

TABLE II Concentration of A log E at 0.6 density Addenda in Addendaprehardener Cyan Magenta Yellow Control 1 05 1.5 Compound 12 100 mg. perliter. 3 2 2 Essentially similar results are obtained when compounds 2,7 or 9 are substituted for compound 12. Also, substantially identicalresults are obtained when compound 12 is incorporated in the bathfollowing the prehardener, or in the MQ developer, rather than in theprehardener.

The highly unobvious nature of this invention is emphasized by the factthat compounds closely related to 4-thiazoline-2-thiones, such as3-carboxyethyl-4-methyl thiazoline 2 thione; 2,2 dithio[5,4 (1,2 D-tritylgluco)]-thiazole; 2-arnin05-thiaz0le carboxylic acid; or,di-(2-amino-4methylthiazole-S-yl)-sulfide, do not produce undercutinterimage effects.

The invention has been described in detail with particular reference topreferred embodiments thereof, but, it will be understood thatvariations and modifications can be effected within the spirit and scopeof the invention.

I claim:

1. In the process of providing multicolor photographic records whichincludes (1) developing silver images in an exposed photographic elementhaving at least two superposed hydrophilic colloid layers containinglightsensitive silver halide, and (2) forming differently colored dyeimages in proportion to said silver images: the improvement whichcomprises introducing a diffusible 4- thiazoline-Z-thione into theexposed photographic element so that the 4-thiazoline-2-thione ispresent during the development of the silver images, whereby undercutinterimage effects are obtained for at least one of the dye images insaid multicolor photographic reproduction.

2. A process of providing multicolor photographic records as defined inclaim 1 wherein the silver halide of at least one of said layerscomprises a silver haloiodide.

3. A process of providing multicolor photographic records as defined inclaim 2 wherein said 4-thiazoline-2- thione has, in the 4-positionthereof, an alkyl substituent having a group selected from the classconsisting of carbonyl and hydroxyl.

4. A process of providing multicolor photographic 12 records as definedin claim 2 wherein said 4-thiaZoline-2- thione contains an alkylsubstituent in the 4-position, said alkyl substituent consisting of from4 to 5 carbon atoms, each of said carbon atoms having a hydroxyl groupattached thereto.

5. A process of providing multicolor photographic records as defined inclaim 2 wherein said 4-thiazoline-2- thione contains, in the 4-positionthereof, a substituent selected from the group consisting of formyl,carboxyl, ethoxycarbonyl, hydroxymethyl, and acetoxymethyl.

6. In the process of providing multicolor photographic records whichincludes (1) developing silver images in an exposed photographic elementhaving at least two superposed hydrophilic colloid layers containinglightsensitive silver halide, at least one of said layers comprisingsilver haloiodide, and (2) forming differently colored dye images inproportion to said silver images: the improvement which comprisesintroducing a difiusible 4-thiazoline-2-thione into the exposedphotographic element so that the 4-thiazoline-2-thione is present duringthe development of the silver images, said 4-thiazoline-2- thione havingthe following general formula:

wherein X represents a substituent selected from the class consisting ofalkyl; an alkyl substituent containing at least one hydroxyl group; and,an alkyl substituent having at least one carbonyl-containing group; and,Z represents a substituent selected from the class consisting ofhydrogen; alkyl; an alkyl substituent containing at least one hydroxylgroup; and, an alkyl substituent containing at least onecarbonyl-containing group, whereby undercut interimage effects areobtained for at least one of the dye images in said multicolorphotographic reproduction.

7. In the process of providing multicolor photographic records whichincludes (1) developing silver images in an exposed photographic elementhaving at least two superposed hydrophilic colloid layers containinglightsensitive silver halide, at least one of said layers comprisingsilver haloiodide, and (2) forming differently colored dye images inproportion to said silver images: the improvement which comprisesintroducing a diffusible 4-thiazoline-2-thione into the exposedphotographic element so that the 4-thiazoline-2-thione is present duringthe development of the silver images, said 4-thiazoline-2- thione beingselected from the group consisting of4-thiazoline-4-carboxaldehyde-Z-thione;5-carbethoxy-4-methyl-4-thiaZoline-2-thione;4-carboxy-4-thiazoline-2-thione;4-carboxy-5-methyl-4-thiazoline-2-thione;4-carbethoxy-4-thiazoline-2-thione;4-acetoxymethyl-4-thiazoline-2-thione; 4- (D-arabinotetraacetoxybutyl)-4-thiaZoline-2-thione; 4- (D-glucopenta-acetoxypentyl)-4-thiazoline-2-thione; 4- (D-gluc openta hydroxyp entyl)-4-thiazoline-2-thione; 4-hydroxymethyl-4-thiazoline-2-thione;4-methyl-4-thiazoline-2-thione; and4-(D-arabino-l,2,3,4-tetrahydroxybutyl)-4-thiazoline-2- thione,

whereby undercut interimage effects are obtained for at least one of thedye images in said multicolor photographic reproduction.

8. In the process for providing multicolor photographic records whichincludes (1) developing silver image records in an exposed photographicelement having coated on a support three superposed hydrophilic colloidlayers container light-sensitive silver halide, said layers beingselectively sensitive to red, green and blue radiation, which silverimages are records for the red, green and blue portions of an object,and (2) forming cyan, magenta and yellow dye images, respectively, inproportion to said red, green and blue silver image records: theimprovement which comprises introducing a diffusible 4-thiazoline-Z-thione into the exposed photographic element so that the4-thiazoline-2-thione is present during the development of the silverimage records, whereby undercut interimage effects are obtained for atleast one of said dye images.

9. A process of providing multicolor photographic records as defined inclaim 8 wherein at least one of said layers comprises light-sensitivesilver bromoiodide.

10. A process of providing multicolor photographic records as defined inclaim 9 wherein said 4-thiazoline-2- thione has, in the 4-positionthereof, an alkyl substituent having a group selected from the classconsisting of carbonyl and hydroxyl.

11. A process of providing multicolor photographic records as defined inclaim 9 wherein said 4-thiazoline-2- thione contains an alkylsubstituents in the 4-position, said alkyl substituent consisting offrom 4 to carbon atoms, each of said carbon atoms having a hydroxylgroup attached thereto.

12. A process of providing multicolor photographic records as defined inclaim 9 wherein said 4-thiazoline-2- thione contains in the 4-positionthereof, a substituent selected from the group consisting of formyl,carboxyl, ethoxycarbonyl, hydroxymethyl and acetoxymethyl.

13. In the process for providing multicolor photographic records whichincludes (1) developing silver image records in an exposed photographicelement having coated on a support three superposed hydrophilic colloidlayers containing light-sensitive silver halide, said layers beingselectively sensitive to red, green and blue radiation, which silverimages are records for the red, green and blue portions of an object,and (2) forming cyan, magenta and yelow dye images, respectively, inproportion to said red, green and blue silver image records: theimprovement which comprises introducing a diffusible 4-thiazoline-2-thione into the exposed photographic element so that the4-thiazoline-2-thione is present during the development of the silverimage records, whereby undercut interimage effects are obtained for atleast one of said dye images, said 4-thiazoline-2-thione having thefollowing general formula:

wherein X represents a substituent selected of the class consisting ofalkyl; an akyl substituent containing at least one hydroxy group; and analkyl substituent having at least one carbonyl-containing group; and, Zrepresents a substituent selected from the class consisting of hydrogen;alkyl; an alkyl substituent containing at least one hydroxyl group; and,an alkyl substituent containing at least one carbonyl-containing group.

14. In the process for providing multicolor photographic records whichincludes (1) developing silver image records in an exposed photographicelement having coated on a support three superposed hydrophilic colloidlayers containing light-sensitive silver halide, said layers beingselectively sensitive to red, green and blue radiation, which silverimagw are records for the red, green and blue portions of an object, and(2) forming cyan, magenta and yellow dye images, respectively, inproportion to said red, green and blue silver image records: theimprovement which comprises introducing a diffusible4-thiazoline-2-thione into the exposed photographic element so that the4-thiazoline-2-thione is present during the development of the silverimage records, whereby undercut interimage effects are obtained for atleast one of said dye images, which 4-thiazoline-2-thione is selectedfrom the group consisting of 4-thiazoline-4-carboxa1dehyde-2-thione;

5 -carbethoxy-4-methyl-thiazoline-Z-thione;

4-carboxy-4thiazoline-2-thione;

4-carboxy-5-methyl-4-thiazoline-2-thione;

4-carbethoxy-4-thiazoline-2-thi0ne;

4-acetoxymethyl-4-thiazoline-2-thione;

4- (D-arabino-tetraacetoxybutyl) -4-thiazoline-2-thione;

4- D-gluco-penta-acetoxyphenyl) -4-thiazoline-2-thione;

4- (D-gluco-penta-hydroxyphenyl -4-thiazoline-2-thione;

4-hydroxymethyl-4-thiaZoline-2-thione;

4-methyl-4-thiazoline-2-thione; and

4- D-arabinol ,2,3 ,4-tetrahydroxybutyl) -4-thiazo-line- 2-thione.

15. In a complete photographic reversal color process wherein amultilayer photographic element containing a plurality of differentiallysensitized photographic silver halide emulsion layers is given a firstexposure, followed by development in a photographic developer forproducing a black-and-white silver negative image and a second exposurefollowed by at least one additional development in a photographicdeveloper for producing a color image, the improvement which comprisesintroducing a diffusible 4-thiazoline-2-thione into said photographicelement subsequent to said first exposure so that said 4-thiazoline-2-thione is present during said development which produces silver negativeimage, whereby undercut interimage effects are obtained for at least oneof the dye images in said multicolor photographic reproduction.

16. The photographic reversal color process as described in claim 15wherein at least one of said silver halide emulsion layers comprisessilver bromoiodide.

17. The photographic reversal color process as described in claim 16wherein said silver negative image is developed in the presence of a4-thiazoline-2-thione which has, in the 4-position thereof, an alkylsubstituent having a group selected from the class consisting ofcarbonyl and hydroxyl.

18. The photographic reversal color process as described in claim 16wherein said silver negative image is developed in the presence of a4-thiazoline-2-thione which contains an alkyl substituent in the4-position, said alkyl substitutent consisting of from 4 to 5 carbonatoms, each of said carbon atoms having a hydroxyl group attachedthereto.

19. The photographic reversal color process as described in claim 16wherein said silver negative image is developed in the presence of a4-thiazoline-2-thione which contains, in the 4-position thereof, asubstituent selected from the group consisting of formyl, carboxyl,ethoxycarbonyl, hydroxymethyl, and acetoxymethyl.

20. In a complete photographic reversal color process wherein amultilayer photographic element containing a plurality of differentiallysensitized photographic silver halide emulsion layers is given a firstexposure, followed by development in a photographic developer forproducing a black-and-white silver negative image and a second exposurefollowed by at least one additional development in a photographicdeveloper for producing a color image, the improvement which comprisesintroducing a diffusible 4-thiazoline-2-thione into said photographicelement subsequent to said first exposure so that said 4-thiazoline-Z-thione is present during said development which produces silvernegative image, whereby undercut interimage effects are obtained for atleast one of the dye images in said multicolor photographicreproduction, said 4-thiazoline-2-thione having the following generalformula:

wherein X represents a substituent selected of the class consisting ofalkyl; an alkyl substituent containing at least one hydroxyl group; andan alkyl substituent having at least one carbonyl-containing group; and,Z represents a substituent selected from the class consisting ofhydrogen; alkyl; an alkyl substituent containing at least one hydroxylgroup; and, an alkyl substituent containing at least onecarbonyl-containing group.

21. In a complete photographic reversal color process wherein amultilayer photographic element containing a plurality of differentiallysensitized photographic silver halide emulsion layers is given a firstexposure, followed by development in a photographic developer forproducing a black-and-white silver negative image and a second exposurefollowed by at least one additional development in a photographicdeveloper for producing a color image, the improvement which comprisesintroducing a diffusible 4-thiaZoline-2-thione into said photographicelement subsequent to said first exposure so that said 4-thiazoline2-thione is present during said development which produces silver negativeimage whereby undercut effects are obtained for at least one of the dyeimages in said multicolor photographic reproduction, said4-thiazoline-2-thione being selected from the group consisting of4-thiazoline-Z-carboxaldehyde-2-thione;S-car-bethoxy-4-rnethyl-4-thiazoline-2-thione;4-carboxy-4-thiazoline-Z-thione;4-carboxy-5-methyl-4-thiaZoline-2-thione;4-carbethoxy-4-thiazoline-2-thione;4-acetoxymethyl-4-thiazoline-Z-thione; 4- D-arabino-tetraacetoxybutyl-4-thiazoline-2-thione; 4- D-gluco-penta-acetoxypentyl-4-thiazoline-2-thione; 4- (D-gluco-penta-hydroxypentyl)-4-thiazoline-2-thione; 4-hydroxymethyl-4-thiazoline-2-thione;4-methyl-4-thiazoline-2-thione; and 4- (D-arabino- 1,2,3,4-tetra-hydroxybutyl) -4-thiazoline-2- thione.

22. In a complete photographic reversal color process wherein amultilayer photographic element containing a plurality of differentiallysensitized photographic silver halide emulsion layers is given a firstexposure, followed by development in a photographic developer forproducing a black-and-white silver negative image and a second exposurefollowed by at least one additional development in a photographicdeveloper for producing a color image, the improvement which comprisesintroducing a diffusible 4-thiazoline-2-thione into said photographicelement subsequent to said first exposure so that said 4-thiazoline-2-thione is present during said development which produces silver negativeimage, whereby undercut interimage effects are obtained for at least oneof the dye images in said multicolor photographic reproduction, said4-thiazoline-2-thione being 4-(D-arabino1,2,3,4-tetrahydroxybutyl)-4thiazoline-2-thione.

23. A photographic reversal color process as defined in claim 15 whereineach of said silver halide emulsion layers contains an incorporatedcolor former which produces dye images upon reaction with oxidizedprimary aromatic color developing agent, and each of said dye imagesbears a complementary relationship to the region of the spectrum towhich the photographic silver halide emulsion has been differentiallysensitized.

24. A process of providing multicolor photographic records as defined inclaim 1 wherein said diifusible compound is incorporated in thedeveloper used to form said silver images.

25. A process of providing multicolor records as defined in claim 1wherein said development is conducted at a temperature of from 68 to 180F.

26. A process of providing multicolor records as defined in claim 6wherein said development is conducted at about F.

27. A process of providing multicolor records as defined in claim 8wherein said development is conducted at a temperature of from 68 to F28. A process of providing multicolor records as defined in claim 13wherein said development is conducted at a temperature of from 68 to 180F.

29. A process of providing multicolor records as defined in claim 15wherein said development is conducted at a temperature of from 68 to 180F.

30. A process of providing multicolor records as defined in claim 20wherein said development is conducted at a temperature of from 68 to 180F.

31. In a complete photographic reversal color process wherein amultilayer photographic element comprising a support having coatedthereon a blue sensitive silver bromoiodide emulsion layer containingyellow dye former, a green sensitive silver bromoiodide emulsion layercontaining magenta dye former, and a red sensitive layer containing cyandye former is given a first exposure, followed by development in aphotographic developer for producing a black-and-white silver negativeimage and a second explosure followed by at least one additionaldevelopment in a photographic primary aromatic amino developing agent toproduce dye images: the improvement which comprises incorporatingapproximately 4.2x 10- moles4-(D-arabino-1,2,3,4-tetra-hydroxybutyl)-4-thiazoline-2-thione per litreof said developer for producing black-and-white silver negative images.

References Cited FOREIGN PATENTS 7/1934 Great Britain. 9/1939 Germany.

US. Cl. X.R. 9659

